The overall objective of this study is to continue determining the indigenous (autochthonous) anaerobic microorganisms and their biochemical interactions in the cockroach gut. Also of concern is where and how the obligate anaerobes which are the predominant flora of the colon colonize. Location of various morphotypes will be ascertained by fluorescent antibody techniques and an immunolatex technique applicable to scanning electron microscopic analysis. Attempts will be made to recolonize anaerobe-free roaches by single species and mixtures of metabolic types. The nature of microbial attachment will be examined by specific staining for EM (ruthenium red, alcian blue-lanthanum) and a lectin-fluorescent antibody technique. Methanogenic, chitinolytic, uricolytic, cellulolytic, and N2-fixing activities will be examined. Efforts will be expanded to isolate, identify, and determine the metabolic potentials of numerous unique morphotypes which have been characterized by electron microscopy. A dark-band area at a specific location in the colon was found to be high in sulfide and to be inhabited by at least 2 unique morphotypes. The origin of the sulfide at this specific site will be investigated.